<template>
  <div class="commnet-container">
    <!-- 评论列表 -->
    <div class="cmt-list" :class="isShow ? 'box1' : 'box2'">
      <!-- 评论的 Item 项 -->
      <div class="cmt-item" v-for="obj in commentList" :key="obj.com_id">
        <!-- 头部区域 -->
        <div class="cmt-header">
          <!-- 头部左侧 -->
          <div class="cmt-header-left">
            <img :src="obj.aut_photo" alt="avatar" class="avatar" />
            <span class="uname">{{ obj.aut_name }}</span>
          </div>
          <!-- 头部右侧 -->
          <div class="cmt-header-right">
            <van-icon
              v-if="obj.is_liking"
              name="like"
              size="16"
              color="red"
              @click="likeOrDislikeFn(obj)"
            />
            <van-icon
              v-else
              name="like-o"
              size="16"
              color="gray"
              @click="likeOrDislikeFn(obj)"
            />
          </div>
        </div>
        <!-- 主体区域 -->
        <div class="cmt-body">
          {{ obj.content }}
        </div>
        <!-- 尾部区域 -->
        <div class="cmt-footer">{{ $timeAgo(obj.pubdate) }}</div>
      </div>
    </div>
    <!-- 底部添加评论区域 - 1 -->
    <div class="add-cmt-box van-hairline--top" v-if="isShow">
      <van-icon name="arrow-left" size="0.48rem" @click="$router.back()" />
      <div class="ipt-cmt-div" @click="isShow = false">发表评论</div>
      <div class="icon-box">
        <van-badge :content="total" max="99">
          <van-icon name="comment-o" size="0.53333334rem" @click="scrollFn" />
        </van-badge>
        <van-icon name="star-o" size="0.53333334rem" />
        <van-icon name="share-o" size="0.53333334rem" />
      </div>
    </div>

    <!-- 底部添加评论区域 - 2 -->
    <div class="cmt-box van-hairline--top" v-else>
      <textarea
        v-model.trim.lazy="content"
        placeholder="友善评论、理性发言、阳光心灵"
        v-focus
        @blur="onBlurFn"
      ></textarea>
      <van-button type="default" @click="publishFn">发布</van-button>
    </div>
  </div>
</template>

<script>
// 目标：发布评论
// 1. 定义接口
// 2. 收集文本域内容 -> v-model="content"
// 3. 点击了发布按钮 -> 给按钮绑定点击事件
// 4. 调接口 -> 内容传递给后台
// 5. 把新的评论对象添加到commentList数组的头部
import {
  getArticleCommentAPI,
  likeCommentAPI,
  dislikeCommentAPI,
  publishCommentAPI
} from '@/api/Article'
export default {
  name: 'Comment',
  data () {
    return {
      commentList: [], // 评论列表
      isShow: true, // 控制评论的第一套结构可见性
      total: null, // 评论的总数量，null不会显示在标签中
      content: '' // 评论的内容
    }
  },
  async created () {
    const resp = await getArticleCommentAPI({
      articleId: this.$route.query.art_id,
      offset: this.offset // 分页，每次后台返回的 last_id的值需要记录下来
    })
    // 解构出last_id 和 results数组，存起来
    const { last_id, results, total_count } = resp.data
    this.offset = last_id
    this.commentList = results
    this.total = total_count || null
  },
  methods: {
    // 评论 喜欢 或 不喜欢
    async likeOrDislikeFn (obj) {
      try {
        obj.is_liking
          ? await dislikeCommentAPI({ commentId: obj.com_id })
          : await likeCommentAPI({ commentId: obj.com_id })
        this.$toast.success(obj.is_liking ? '取赞成功' : '点赞成功')
        obj.is_liking = !obj.is_liking
      } catch (e) {
        this.$toast.fail(obj.is_liking ? '取赞失败' : '点赞失败')
      }
    },
    // 让点赞的盒子滚动到视口底部
    scrollFn () {
      const el = document.querySelector('div.like-box')
      el.scrollIntoView({
        behavior: 'smooth' // 开启动画模式
      })
    },
    // 发布评论
    async publishFn () {
      if (!this.content) return
      const resp = await publishCommentAPI({
        articleId: this.$route.query.art_id,
        content: this.content
      })
      this.commentList.unshift(resp.data.new_obj)
      this.content = ''
    },
    // 文本域失焦
    onBlurFn () {
      // 让文本域异步隐藏 -> 加个延迟器即可
      setTimeout(() => {
        this.isShow = true
      })
    }
  }
}
</script>

<style scoped lang="less">
.cmt-list {
  padding: 10px;
  .cmt-item {
    padding: 15px 0;
    + .cmt-item {
      border-top: 1px solid #f8f8f8;
    }
    .cmt-header {
      display: flex;
      align-items: center;
      justify-content: space-between;
      .cmt-header-left {
        display: flex;
        align-items: center;
        .avatar {
          width: 40px;
          height: 40px;
          background-color: #f8f8f8;
          border-radius: 50%;
          margin-right: 15px;
        }
        .uname {
          font-size: 12px;
        }
      }
    }
    .cmt-body {
      font-size: 14px;
      line-height: 28px;
      text-indent: 2em;
      margin-top: 6px;
      word-break: break-all;
    }
    .cmt-footer {
      font-size: 12px;
      color: gray;
      margin-top: 10px;
    }
  }
}

// 发布评论的盒子 - 1
.box1 {
  padding-bottom: 46px;
}
// 发布评论的盒子 - 2
.box2 {
  padding-bottom: 80px;
}
.add-cmt-box {
  position: fixed;
  bottom: 0;
  left: 0;
  width: 100%;
  box-sizing: border-box;
  background-color: white;
  display: flex;
  justify-content: space-between;
  align-items: center;
  height: 46px;
  line-height: 46px;
  padding-left: 10px;
  .ipt-cmt-div {
    flex: 1;
    border: 1px solid #efefef;
    border-radius: 15px;
    height: 30px;
    font-size: 12px;
    line-height: 30px;
    padding-left: 15px;
    margin-left: 10px;
    background-color: #f8f8f8;
  }
  .icon-box {
    width: 40%;
    display: flex;
    justify-content: space-evenly;
    line-height: 0;
  }
}
.child {
  width: 20px;
  height: 20px;
  background: #f2f3f5;
}
// 发布评论的盒子 - 2
.cmt-box {
  position: fixed;
  bottom: 0;
  left: 0;
  width: 100%;
  height: 80px;
  display: flex;
  justify-content: space-between;
  align-items: center;
  font-size: 12px;
  padding-left: 10px;
  box-sizing: border-box;
  background-color: white;
  textarea {
    flex: 1;
    height: 66%;
    border: 1px solid #efefef;
    background-color: #f8f8f8;
    resize: none;
    border-radius: 6px;
    padding: 5px;
  }
  .van-button {
    height: 100%;
    border: none;
  }
}
</style>
